Conventionally, as such a flow meter device, it is known that plural fluid passages are provided with on-off valves, respectively (e.g., see Patent Literature 1).
FIG. 6 is a block diagram showing the configuration of a conventional flow meter device disclosed in Patent Literature 1.
As shown in FIG. 6, a flow meter device 100 disclosed in Patent Literature 1 is configured in such a manner that plural fluid passages 103 are provided between an inflow passage 101 and an outflow passage 102, and opening/closing units 104 and measuring units 105 are provided to correspond to these fluid passages 103, respectively.
In the flow meter device disclosed in Patent Literature 1, a control unit (power supply monitoring unit) controls electric power supplied from a power supply unit 107 to the opening/closing units 104. In this configuration, in the flow meter device 100 disclosed in Patent Literature 1, when the fluid passage through which the fluid flows is chosen according to the flow (flow rate) of the fluid flowing through the flow meter device 100, the control unit 106 is able to perform control such that the power supply unit 107 stops supplying electric power to the opening/closing unit 104 maintained in a closed state or in an open state. This can lessen a wasteful current.